//You are given an integer array prices where prices[i] is the price of a given 
//stock on the ith day, and an integer k. 
//
// Find the maximum profit you can achieve. You may complete at most k transacti
//ons. 
//
// Note: You may not engage in multiple transactions simultaneously (i.e., you m
//ust sell the stock before you buy again). 
//
// 
// Example 1: 
//
// 
//Input: k = 2, prices = [2,4,1]
//Output: 2
//Explanation: Buy on day 1 (price = 2) and sell on day 2 (price = 4), profit = 
//4-2 = 2.
// 
//
// Example 2: 
//
// 
//Input: k = 2, prices = [3,2,6,5,0,3]
//Output: 7
//Explanation: Buy on day 2 (price = 2) and sell on day 3 (price = 6), profit = 
//6-2 = 4. Then buy on day 5 (price = 0) and sell on day 6 (price = 3), profit = 3
//-0 = 3.
// 
//
// 
// Constraints: 
//
// 
// 0 <= k <= 100 
// 0 <= prices.length <= 1000 
// 0 <= prices[i] <= 1000 
// 
// Related Topics 数组 动态规划 
// 👍 534 👎 0


package leetcode.editor.cn;

//Java：Best Time to Buy and Sell Stock IV
class P188BestTimeToBuyAndSellStockIv {
    public static void main(String[] args) {
        Solution solution = new P188BestTimeToBuyAndSellStockIv().new Solution();
        // TO TEST
    }

    //leetcode submit region begin(Prohibit modification and deletion)
    class Solution {
        public int maxProfit(int j, int[] prices) {
            if (prices.length <= 1) {
                return 0;
            }
            int n = prices.length;
            int[][][] dp = new int[n][j + 1][2];
            for (int i = 0; i < n; i++)
                for (int k = j; k >= 1; k--) {
                    if (i - 1 == -1) {
                        dp[i][k][0] = 0;
                        dp[i][k][1] = -prices[i];
                        continue;
                    }
                    dp[i][k][0] = Math.max(dp[i - 1][k][0], dp[i - 1][k][1] + prices[i]);
                    dp[i][k][1] = Math.max(dp[i - 1][k][1], dp[i - 1][k - 1][0] - prices[i]);
                }
            return dp[n - 1][j][0];
        }
    }
//leetcode submit region end(Prohibit modification and deletion)

}